More than 40% of ex-NFL players may have signs of brain injury

A recent study has indicated that, based on diffusion tensor imaging, >40% of retired National Football League (NFL) players may exhibit signs of traumatic brain injury (TBI). The results of the research will be presented at the American Academy of Neurology’s 68th Annual Meeting commencing this week (15–21 April 2016, Vancouver, Canada).

In the study, which was led by researchers at Florida State University College of Medicine (FL, USA), 40 retired NFL players participated in a range of thinking and memory tests, as well as brain scans. The average age of the players was 36 years and the majority had left the NFL less than 5 years earlier, after competing for an average of 7 years within the league.

The cohort of players had experienced on average 8.1 concussions during their careers and 31% of them confirmed that they had also been subject to several sub-concussive hits.

Utilizing MRI, white matter damage within the brains of the players was assessed. Approximately 30% of the study group exhibited signs of disruption to the nerve axons, with those having spent more time in the NFL more likely to show signs of TBI. However, there was no evidence of a relationship between the number of concussions experienced and hallmarks of TBI on the MRI scans.

Cognitive tests indicated that 50% of the player group had problems with executive functioning and 45% had issues with learning and/or memory. Attention and concentration was also affected in 42% of individuals and spatial and perceptual function in 24%. Finally, 43% of players demonstrated movement levels 2.5 standard deviations below those of healthy people of the same age, which is considered evidence of traumatic brain injury with a less than one percent error rate.

“This is one of the largest studies to date in living retired NFL players and one of the first to demonstrate significant objective evidence for traumatic brain injury in these former players,” commented lead author of the study, Francis X. Conidi (Florida State University College of Medicine).

He concluded: “This research in living players sheds light on the possible pathological changes consistent with chronic traumatic encephalopathy that may be taking place.”